If you are in Majorca having a package holiday but would like to visit one of the other Balearic islands during your holiday then it is actualy a relatively easy process to book a ferry/boat trip to one of the other islands.
3 companies that offer ferry journeys from Majorca to Ibiza, Minorca and Fermentera
http://www.iscomar.com/
http://www.balearia.com/
http://www.trasmediterranea.es/trasmeweb/inicio.do
